To change, or not to change, that is the question…

[jenniferlouise]

I’ve been thinking… as many here have experienced, the OEM 19” 326M alloys had some cracks evident when we popped them off to upgrade the brake callipers and discs. Given that new they are £550+vat, plus mine aren’t stock colour, I’ve had them repaired…

Just been told that I’ve already sprung another crack… which means I can’t get an MoT on the car today. I guess my options now are:
a) repair again (it’s already got 6 fixes)
b) buy second hand wheel(s) (limited availability and no guarantee it’s any better)
c) buy BMW again (x2 and colour match or x4 and return to standard)
d) buy non OEM, change the look and benefit from non RFTs

I guess I’m already talking myself into option d) unless I can find a single wheel b) HELP!

 

[B21]

IMHO if you plan to keep the Z4 option d is your only recourse..

Of the 5 sets of wheels I've had (apart from 326m) none have cracked..

To reflect others..if I was going 19" then I would go with a brand not noted for cracking like Veeman, Zito etc

High price for 19" in terms of costs, weight, ride quality compared to 18" FWIW

 

[jenniferlouise]

Thanks. I’m not ruling out an 18” rim, as appreciate the benefits, but it does look terrific on its 19”s (I know, I’m that shallow) .

It’s been suggested to me to slightly increase the profile… so keep a 19” and add a 35 profile to the rear in place of 30 and similarly 40 in place of 35 to front. Obviously non RFTs too. This, I’m told, will make a big ride difference.

Interested to hear / read anyones replacement options. I’ll be using the search too in order o seek out some historical options.

 

[Mr Tidy]

Those 326s and run-flats do seem to be a terrible combination.

I don't know what model your E89 is but I've got a set of 17" Style 290s going cheap - albeit with Bridgestone run-flats, but they do have 45 profile tyres on. If nothing else they'd get you through the MOT!

https://z4-forum.com/forum/viewtopic.php?p=1896898&hilit=290#p1896898

 

[jenniferlouise]

Those 326s and run-flats do seem to be a terrible combination.

I don't know what model your E89 is but I've got a set of 17" Style 290s going cheap - albeit with Bridgestone run-flats, but they do have 45 profile tyres on. If nothing else they'd get you through the MOT!

https://z4-forum.com/forum/viewtopic.php?p=1896898&hilit=290#p1896898

Thank you I’ve a 23i M Sport however I’m also running larger front discs and M Performance callipers. If your 17” will wrap around them, I may well be very interested. As you say, I can then get the car out of the garage and MoT’d. I may even like the ride improvements. Fee free to DM me. I could give the RAV4 a ride out

 

[B21]

Those 326s and run-flats do seem to be a terrible combination.

I don't know what model your E89 is but I've got a set of 17" Style 290s going cheap - albeit with Bridgestone run-flats, but they do have 45 profile tyres on. If nothing else they'd get you through the MOT!

https://z4-forum.com/forum/viewtopic.php?p=1896898&hilit=290#p1896898

Thank you I’ve a 23i M Sport however I’m also running larger front discs and M Performance callipers. If your 17” will wrap around them, I may well be very interested. As you say, I can then get the car out of the garage and MoT’d. I may even like the ride improvements. Fee free to DM me. I could give the RAV4 a ride out

17” wheels with M performance calipers n discs is a very tight squeeze…I found 103 daisies actually bound..my Team Dynamics Pro Race 1.2 didn’t…

 

[Smartbear]

Those 326s and run-flats do seem to be a terrible combination.

I don't know what model your E89 is but I've got a set of 17" Style 290s going cheap - albeit with Bridgestone run-flats, but they do have 45 profile tyres on. If nothing else they'd get you through the MOT!

https://z4-forum.com/forum/viewtopic.php?p=1896898&hilit=290#p1896898

Thank you I’ve a 23i M Sport however I’m also running larger front discs and M Performance callipers. If your 17” will wrap around them, I may well be very interested. As you say, I can then get the car out of the garage and MoT’d. I may even like the ride improvements. Fee free to DM me. I could give the RAV4 a ride out

My 20i drives like a sofa with 17’s fitted, potholes mysteriously disappear
Rob

 

[Mr Tidy]

I don't know anything about the M-Performance brakes on the E89 as I haven't had an E89!

But they were fine on my E90 330i with 330mm front discs.

Although B21 suspects they may not work - perhaps the bigger caliper needs more clearance?

Hopefully someone will know!

 

[B21]

I don't know anything about the M-Performance brakes on the E89 as I haven't had an E89!

But they were fine on my E90 330i with 330mm front discs.

Although B21 suspects they may not work - perhaps the bigger caliper needs more clearance?

Hopefully someone will know!

The rotors are 338mm…

I know the hard way that even 28i 330mm calipers and discs don’t fit 103 daisys..fitted them , bolted the wheels on, then the car wouldn’t move..

 

[jenniferlouise]

I don't know anything about the M-Performance brakes on the E89 as I haven't had an E89!

But they were fine on my E90 330i with 330mm front discs.

Although B21 suspects they may not work - perhaps the bigger caliper needs more clearance?

Hopefully someone will know!

Caught in a dilemma now :? my discs are 330 too. Having measured, looks to be about 30mm clearance between current 19” 326M alloy and the Performance calliper, which don’t come further forward than the wheel hub. I suspect, if these rims fitted the E90, it would fit the Z4. It’s a long way to come to get it wrong… but at the mo I can’t go anywhere in the Zed anytime soon.

Couple of pics to show my point.

 

[B21]

18” wheels will fit no issue…17” you are at risk on some and some definitely won’t fit..

FWIW 18” seem to be the sweet spot handling / comfort wise..

Almost all the comfort of 17” and almost all the ‘performance’ of the 19”

I’ve tried all 3 on two E89s 20i and 35is and that’s my conclusion too..

 

[jenniferlouise]

Cheers, all helpful info. A 30mm gap will be just about swallowed up by a 2” drop (25mm each side) so now I’m sweating on it. I’ll look again see if I can find an old, unrepaired 326M first. Long term, if the car is destined to stay another year, I’d like to change them. Either 18” or I’ve been advised a 19” with a higher profile (35 and 40, not 30 and 35) and non RFTs. But that’s probably £1500-2000 investment, which needs planning for. And I’d like the opportunity to try a few, so that’s probably a trip to Eastbourne and BMAutosport

I’m off to walk the dogs. This is too hard!

 

[sars]

I wouldn’t say it is worth taking the risk of buying a set of 17” wheels with callipers that big. I know it may seem daunting swapping wheels, but there’s plenty of help both here and online to guide you, some things to consider below and sorry if I’m teaching you to suck eggs

Staggered or square? Only the MSport models and the 35i & 35iS came with staggered as standard and only the turbo 6’s probably needed it
Your wheels are 8J x 19 ET29 and 9J x 19 ET40 and tyres 225/35 R19 & 255/30 R19
Try and keep the circumference of the tyre to +/- 5% of original, changing circumference alters the speedo accuracy
Keep the offset to +/-5mm of the original, else you will need the hassle of spacers, offset simply is the lower the number the further they will poke out. If you go square the offset for the rears will be the same as the fronts
The wider the tyres, the more noise they generate
The lower the profile the stiffer the side wall and the less comfortable the ride will be, 255/30R19 make for both a noisy cabin and an uncomfortable ride
TPMS, older e89 use the abs system, later models use individual wheel sensors
You can buy wheel and tyre packages, which usually works out cheaper, BM Autosport is a good place as is Demon Tweaks
A good way to learn offsets and how changing rim width effects things is https://www.willtheyfit.com/

 

[john-e89]

Can you not buy a rear 326 off eBay, have it refurbed to the same colour and fit new non run flat rubber Jen...?

Think I've had about 5 35is's on MPSS non run flats on 326's and never had a crack. The ride is Mr softy wafty on them.

Appreciate Derbyshire is a long way to travel but you're welcome to come up and take my 35 out on the above to see for yourself.

 

[jenniferlouise]

John, sars, thank you both. Great information. I will have a look at the ‘willtheyfit’ site when considering options. As of this afternoon, I’m thinking of moving to the M2 etc alloys (437M). I mocked up an image and they look pretty good (being polished / black on a black Z4), with a similar yet more contemporary look. I believe these are larger 9J with 255/35 and 10J w/ 275/35. I’m informed here and elsewhere these would fit. Certainly look great and maintain BMW figment. Also, being forced, they are much harder (cleary designed for bigger loading than my 200ps). I still might buy a single 326 and refurb, but they aren’t easy to find (and when you find one the seller doesn’t want to engage), but knowing their vulnerability - appreciating John’s comments about their improvement moving off RFTs - it doesn’t feel like progress. £200 on some excellent welding wasn’t enough to get me through an MoT this week... Any further thoughts?

 

[tiglon]

I would add that the tyres that M2/M3/M4 wheels come with are not ideal for a Z4 and might not fit. You may get some rubbing at the front with 255/35, and the 275/35 at the back will increase the diameter which might cause issues. Not saying it definitely won't work, but something to consider - others might be able to advise better than me.

As per your other post, it is a £1500+ investment if you don't already have tyres to put on. And, by investment, I mean money spent that you'll never get back

 

[Mr Tidy]

I don't know anything about the M-Performance brakes on the E89 as I haven't had an E89!

But they were fine on my E90 330i with 330mm front discs.

Although B21 suspects they may not work - perhaps the bigger caliper needs more clearance?

Hopefully someone will know!

Caught in a dilemma now :? my discs are 330 too. Having measured, looks to be about 30mm clearance between current 19” 326M alloy and the Performance calliper, which don’t come further forward than the wheel hub. I suspect, if these rims fitted the E90, it would fit the Z4. It’s a long way to come to get it wrong… but at the mo I can’t go anywhere in the Zed anytime soon.

Couple of pics to show my point.

If the distance wasn't so great a trial fit might be viable, but as you say it's a bit too far to find out they don't!

I bought a set of 18" E89 Style 295s on here for my previous E86 but there don't seem to be any 18s in the classifieds just now.

Good luck finding a solution.

 

[john-e89]

My thoughts were your cheapest option and that you like 326's Jen which I do too, but can very much understand your hesitation to go that way.

My 35i is on 235\35\19 fronts and 275\30\19 rear 437's, I 'think' the fronts maybe a little stretched and require a 245 tyre, however I have zero rubbing and that's with a 20mm drop from M sport springs, so 30mm from non M sport springs. I've also added 10mm spacers all round to clear the front spring perches on the KW coil overs and still never had a rub, front or rear, for your info.

 

[jenniferlouise]

I’ve been playing with the ‘willtheyfit’ configuration website, to see what happens if I were to swap on M2 style 437...
the front (8J 225/35 to 9J 255/35) adds 21mm diameter, 12.7mm equally to the width, 3% Speedo error, 10mm ride height gain and 10mm loss in the arch
the rear (9J 255/30 to 10J 275/35) adds 40mm diameter, 12.7mm equally to width, 5% Speedo error, 20mm ride height gain and 20mm loss in the arch.
That doesn’t seem too bad, but needs some tape measuring tomorrow. I am still looking for a 326 9J 19” rear too. For now, Z4 remains looking all dressed up and nowhere to go in the garage.

 

[Darkangelv2]

437M is a great shout -

- Vanishingly few reports of cracking on this wheel - known quality OEM items
- Substantially lighter than your current wheels, so real world performance benefit (Roughly 2KG saving per wheel!)
- Cheaper than new wheels
- They look great